Th[e] response hasn’t changed over time, through the June surge and into today’s decline, so there’s no definitive explanation for the flattening, though, and experts have several theories.
“Swedes in general have changed their behavior to a great extent during the pandemic and the practice of social distancing as well as physical distancing in public places and at work has been widespread,” said Maria Furberg, MD, PhD, an infectious diseases expert at Umea University Hospital in northeastern Sweden.
“During the months of March to early June, all shops were practically empty, people stopped dining with friends, and families stopped seeing even their closest relatives,” Furberg told MedPage Today. “A lock-down could not have been more effective. Handwashing, excessive use of hand sanitizers, and staying home at the first sign of a cold became the new normal very quickly.”
Mozhu Ding, PhD, an epidemiologist at the famed Karolinska Institute, said the decline is “likely to be a combination of measures taken by individuals, businesses and a widespread information campaign launched by the government.”
“Even without a strict lockdown order, many businesses allowed employees to work from home, and universities are offering distance courses to the students,” Ding told MedPage Today. “Individuals are also taking personal hygiene more seriously, as items like hand sanitizers and single-use gloves are often sold out in pharmacies and grocery stores.”
Experts told MedPage Today there weren’t clear data to prove Tegnell’s assertion of widespread immunity in Sweden.
Furberg said there is likely “some sort of unspecific immunity that protects parts of the population from contracting #COVID-19” but it’s not necessarily secondary to #SARS-CoV-2 exposure.
For instance, a study by the Karolinska Institute and Karolinska University Hospital recently found that about 30% of people with mild or asymptomatic COVID showed T-cell-mediated immunity to the virus, even though they tested negative for antibodies.
“This figure is [more than] twice as high as the previous antibody tests, meaning that the public immunity to COVID-19 is probably much higher than what antibody studies have suggested,” Ding told MedPage Today. “This is of course very good news from a public health perspective, as it shows that people with negative antibody test results could still be immune to the virus at a cellular level.”